Radon is considered an important environmental risk factor for lung cancer. Previous studies have shown that relatively few homes have been tested for radon. Results from the Behavioral Risk Factor Surveillance System from 1989--1992 show significant interstate and demographic variation in levels of radon awareness and home testing. There was evidence that levels of radon awareness and testing homes for radon have increased from 1989 through 1992. Although these trends in the data are encouraging, the data also suggest that continued education and other interventions may be necessary to reach the Public Health Service's testing and mitigating objectives for residential radon.